Someone asked me what PSU I used. I did use a regulator.
But I have a monoblock minitower with lot of heatsink.
It does not means you also have to use a regulator and hence extra dissipation.
Even if you do, you can use a bipolar sziklai instead of a MOSFET as cap multiplier.
That will minimise the dropout voltage.
As for the Conrad MF35-151, it will dissipate 130W at 3°C temperature rise (above ambient).
This is datasheet value.
I don't use them, so I have no measurement to back up.
Patrick
But I have a monoblock minitower with lot of heatsink.
It does not means you also have to use a regulator and hence extra dissipation.
Even if you do, you can use a bipolar sziklai instead of a MOSFET as cap multiplier.
That will minimise the dropout voltage.
As for the Conrad MF35-151, it will dissipate 130W at 3°C temperature rise (above ambient).
This is datasheet value.
I don't use them, so I have no measurement to back up.
Patrick
PCB Progress :
One side copper is done, still one copper side, 2 solder masks, and one component placement.
Looking good.
Patrick
JoyAussie builders, we should get together to save on shipping. Any thoughts? I’m Sydney based.
Please take my word and be patient with the casing.
We will work out a solution to minimise your cost, including people from down under.
But we need time to look at different scenario before we can give you a balanced proposal.
I own no shares of the Australian / US / Deutsche Post.
Patrick
Realistically, we'll be ready to take oders (if we end up that far) no sooner than mid December.
So you won't get it for X'mas.
And then you probably want to wait till AR2 finish the proto and tell you how he builds it.
But you will definitely finish before X'mas 2011.
.
We will work out a solution to minimise your cost, including people from down under.
But we need time to look at different scenario before we can give you a balanced proposal.
I own no shares of the Australian / US / Deutsche Post.
Patrick
Realistically, we'll be ready to take oders (if we end up that far) no sooner than mid December.
So you won't get it for X'mas.
And then you probably want to wait till AR2 finish the proto and tell you how he builds it.
But you will definitely finish before X'mas 2011.
.
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yep, for sure, I still need to decide if i'm going with the chassis, have to see if its excellence is enough to sway me from going with it inside my speaker enclosure as an active (which has been my plan all along) to perhaps sitting directly behind or underneath. but for other parts yes indeed. like sumR trannies, output devices etc.
timing is fine Patrick, i'm in no hurry, no speakers yet and need to put some dollars aside as wallet recovers from recent thrashings, I would be disappointed if you were ready too quickly ;D
timing is fine Patrick, i'm in no hurry, no speakers yet and need to put some dollars aside as wallet recovers from recent thrashings, I would be disappointed if you were ready too quickly ;D
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Did you compare noise? I also have access to a device that can measure under 1mOhm but I think the best method is to tune after the fact with a distortion analyzer. Prebuilt and trimmed F5X modules would be the way to go, but would be 4x the cost probably. Similar to Twisted Pear Audio's approach.
Those "modules" are for people who do not want to learn / understand electronics and not want to pay money for hi-end gear.
Nothing wrong, but if that is what you want, this is probably not the right place, and I am certainly not the right guy for you.
And I have no respect for people who sells standard datasheet implementations.
As much as time allows, I shall try to teach you skills to find food.
I certainly won't spoon feed you. And I bet neither does Nelson.
I mean you generally, not Marc or any specific person.
Patrick
Nothing wrong, but if that is what you want, this is probably not the right place, and I am certainly not the right guy for you.
And I have no respect for people who sells standard datasheet implementations.
As much as time allows, I shall try to teach you skills to find food.
I certainly won't spoon feed you. And I bet neither does Nelson.
I mean you generally, not Marc or any specific person.
Patrick
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point taken, but you're providing a list of suggested brands for parts, then there is the matched FETs, matched JFETs and corresponding resistors, a PCB, a chassis. What's the skill you're teaching again?
I think the answer is how to identify the hard-core DIYers around here who know what they're doing and are imitation worthy. Nothing wrong with that, I have a list of people that I stalk around here and honestly that's the best way to consume information on this site.
Anyways, so what's left but to solder the thing? The nice thing about the module is at least someone would be doing testing and verification after it's built, something that should be done more often around here.
I think the answer is how to identify the hard-core DIYers around here who know what they're doing and are imitation worthy. Nothing wrong with that, I have a list of people that I stalk around here and honestly that's the best way to consume information on this site.
Anyways, so what's left but to solder the thing? The nice thing about the module is at least someone would be doing testing and verification after it's built, something that should be done more often around here.
by in the same enclosure, I mean at the bottom of a tower/stand so that the massive weight of the sinks etc also serves as damping (along with a ton of sand or other anchoring weight). the ATC studio actives are simply some of the best sounding speakers of any sort that I have heard (not that I have heard a massive variety of gear other than at meets) and I am trying to emulate that. surely there is also something to be gained from lowering the distance as well as the accompanying inductance? XO will be external digital, fed by the upcoming 8 channel ackodac and a mac mini running logic pro and RME multichannel IO .
i'm on the lookout for some ATC studio line bass and mid drivers too, they pop up from time to time. not sure on the tweets yet
point taken though
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Marc,
I find your remarks unfair.
You can find enough posts here from me and on the F5 thread which explain in detail the reasoning behind my choice of components (e.g. why Toshiba MOSFETs, why 5R degeneration for the 2SJ74,.... etc. supported by measurement data) and circuit setting (like rail voltage and current, and why they are so chosen). I also explained how you use the symmetry to cancel even harmonics, how you can do even better trade-offs in the F5X which has two axes of symmetry...., etc.
Just as Nelson always explain the principle of his circuits in detail and not just give you a schematics, a BoM, and a Gerber file.
Do you get any of the above from the other place, where you paid the money and get a fully finished PCB just to wire power supplies and fancy housings to ?
For me that is not the type of DIY I want to support. Personal choice, to which I have the right.
You can ignore all these theoretical stuff, and wait for the final results and copy & paste. Fine with me if that is what you want. I cannot force you to learn. You can also buy a fully finished product where all the trimming is done for you -- there is one available much better than anything I can / will do --the FW F5.
You can choose to follow the theories (and there is one person here who does that intensively for the last 2 months, helping me to do spice simulation when I have no time, and making comparisons to different measurement methods, etc, and publishing them), and you might eventually learn enough to be able to design your own circuits. Or at least you understand the circuit enough so that you can debug them yourselves and not scream for help with the first thing that goes wrong.
Your choice, and you have the right to.
And I want to say openly, thank you Dave for doing all the donkey work for me .....
Regards,
Patrick
I find your remarks unfair.
You can find enough posts here from me and on the F5 thread which explain in detail the reasoning behind my choice of components (e.g. why Toshiba MOSFETs, why 5R degeneration for the 2SJ74,.... etc. supported by measurement data) and circuit setting (like rail voltage and current, and why they are so chosen). I also explained how you use the symmetry to cancel even harmonics, how you can do even better trade-offs in the F5X which has two axes of symmetry...., etc.
Just as Nelson always explain the principle of his circuits in detail and not just give you a schematics, a BoM, and a Gerber file.
Do you get any of the above from the other place, where you paid the money and get a fully finished PCB just to wire power supplies and fancy housings to ?
For me that is not the type of DIY I want to support. Personal choice, to which I have the right.
You can ignore all these theoretical stuff, and wait for the final results and copy & paste. Fine with me if that is what you want. I cannot force you to learn. You can also buy a fully finished product where all the trimming is done for you -- there is one available much better than anything I can / will do --the FW F5.
You can choose to follow the theories (and there is one person here who does that intensively for the last 2 months, helping me to do spice simulation when I have no time, and making comparisons to different measurement methods, etc, and publishing them), and you might eventually learn enough to be able to design your own circuits. Or at least you understand the circuit enough so that you can debug them yourselves and not scream for help with the first thing that goes wrong.
Your choice, and you have the right to.
And I want to say openly, thank you Dave for doing all the donkey work for me .....
Regards,
Patrick
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> Too many components that are either microphonic or interact with each other to end up with a low distortion product.
He is right.
Put your hand on a sand filled bookshelf speaker stand playing heavy metal and see for yourself how much vibration you still get. I do not want to put my electronic circuit there. In fact, I put my passive crossover outside the speaker enclosure these days.
Patrick
He is right.
Put your hand on a sand filled bookshelf speaker stand playing heavy metal and see for yourself how much vibration you still get. I do not want to put my electronic circuit there. In fact, I put my passive crossover outside the speaker enclosure these days.
Patrick
> Is there not a contradiction between square PCB, good for heat spreading in tower monobloks, and the choice of a linear chassis using MF35-151?
Yes, there is. And this is why I use tower monoblocks.
The chioce of the Conrad heatsink is cost.
2 of my mini-towers would cost 2.5~3x to make of that one of our proposed housing would cost you.
You can of course design a long and narrow PCB to suit the enclosure.
Please feel free to do so. I just offer what I have off hand without another 20 hours of work.
With a back plate of about 10mm of the Conrad, the difference in the end is about 5°C non-uniform temperature over the heatsink, or in other words 5°C higher temperature at the MOSFET.
Perfection always comes at a price.
Patrick
Yes, there is. And this is why I use tower monoblocks.
The chioce of the Conrad heatsink is cost.
2 of my mini-towers would cost 2.5~3x to make of that one of our proposed housing would cost you.
You can of course design a long and narrow PCB to suit the enclosure.
Please feel free to do so. I just offer what I have off hand without another 20 hours of work.
With a back plate of about 10mm of the Conrad, the difference in the end is about 5°C non-uniform temperature over the heatsink, or in other words 5°C higher temperature at the MOSFET.
Perfection always comes at a price.
Patrick
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